A total or partial obstruction of light from a celestial body caused by its passing into the shadow of another body; also, the hiding of one celestial body by another one: An eclipse occurs most notably when the Moon passes in front of the Sun.

In an eclipse of the Sun, it is the light of the Sun which is totally or partially cut off from the planet Earth by the Moon coming between the two bodies.

A solar eclipse in which a ring (an annulus or the figure bounded by and containing the area between two concentric circles) of solar photosphere remains visible: When a annular eclipse occurs, the moon is too far from the Earth. to completely cover the sun's disk at the time of the eclipse.

The result is a bright ring, or annulus, of light encircling the moon.

The passage of the Moon into the Earth's shadow: A lunar eclipse is a phenomenon in which the Earth covers up the full Moon, either partially or completely.